Serum miRNA will be extracted using a Qiagen RNeasy Mini Kit according to manufacturer protocol. RNA will be processed with the Genisphere FlashTag HSR RNA labeling kit. RNA Spike Control Oligos, and poly(A) tails will be added to each RNA sample and a biotinylated signaling molecule will be ligated to the RNA. The labeled RNA samples will be added to a hybridization cocktail, incubated, and injected into Affymetrix miRNA 2.0 arrays. After 16 hours of hybridization, the arrays will be washed and stained on an Affymetrix fluidics station 450 using protocol FS450_0003. Arrays will be scanned on an Affymetrix GeneChip Scanner 7G Plus. The cel files will be analyzed using miRNA QC Tool version 1.1.1.0.